Induction unit



May 1, 1928.

L. M. MARTlN INDUCTION UNIT Filed Oct.

Lzo zMMart im WITNESS:

ATTORN EY Patented Ma 1,? 1928.

UNITED STATES PATENT OFFICE.

INDUCTION UNIT.

Application filed October 23, 1926. Serial No. 143,772.

This invention relates to ah induction unit for a radio outfit, the general object of the invention being to provide means whereby the amount of wire on the unit can be increased or decreased as desired so as to contiol the length of the waves without the use of a switch or variablecondenser.

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to. be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claim. 1 16 In describing my'invention in detail, reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in Which:

Figure 1 is a plan view with parts in section.

Figure 2 is a section on line 5 of Figure 1.

Figure 3 is a section-0n line 6 6 of Fig- 25' ure 1.

Figure his a section on line 7--7 of Figure 1.

The figures on the drawing show the invention applied to a solenoid coil. In these -the solenoid coil is shown in the Eatube of non-conducting material 'w ich is rotatably supported in the frame 16 of the device. A second tube 17 of metal, such as copper, is also rotatably supported in the frame and a screw threaded shaft 18 is rotatably supported in the frame between the two tubes. This shaft is provided with a knob. 19 by which it can be rotatedand gears 20 connect the shaft with the pintlesiof thetubes sothat movement of the shaft will be communicated tothe tubes. A guiding member 21 has a threaded hole therein which is engaged by" the threaded partof the shaft and a rod 22 passes through a plain hole in the member so that rotary movement of the shaft w ll cause the member to move in one direction or the other in a path parallel with the tubes. This member is provided with an eye 23 at its upper-end for the wire 24 which forms the coils 'of the solenoid tube 15. The member 21 moves sufliciently to space the coils of wire apart on the tube 15 so that no non-conducting means are required to separate the coils of wire. By turning the shaft, the wire will be caused to pass from one tube to the other so that the amountot' wire on the tube 15 can be regulated so that said tube 15 provides a variable coil; the induction of which "is varied without using a tap switch or variable condenser.

The induction unit described can'be used in conjunction with one or more fixed or variable coils, to be used for regeneration sets, and it can also be seen that with this addition it makes the unit adaptable to two,

three and four circuit radio sets. 7

It is thought from the foregoing description that the advantages and novel features of my invention will be readily apparent.

I desire it to be understood that I may make changes in the construction and in the combination and arrangement of the several parts, provided that such changes fall within the scope'of the appended claim.

What I claim is An induction unit for a radio outfit comprising a pair of drums, a screw threaded shaft placed between the drums, means for rotating the shaft,'means for communicating the movement of the shaft to the drums,

a guidin member having a threaded hole therein through which the shaft passes and." a wire having each end connected to each drum and passing through"- the guiding member so that-as the shaft is turned, por tions of the wire will pass from one drum to the other and the guiding-member will space th coils of wire from each other.

In testimony whereof I afiix m si ature.

. LLOYD n. ifmi irm, 

